Manufacture of stay tapes



March 12, 194..` H. A'I'WAI'ER MANUFACTURE 0F STAY TAPES Original FiledJune 9, 1936 Patented Mar. y12, 194i) UNITED STATESY Mmm-Acme or sur'raras Henry Atwater, Worcester, Mass.

original application rune 9, 193s, .serial No.ik

84,335. Divided and this` application 1937, Serial N19. Md

May 14,

i amm; (ci. 154-2),

The present invention relates to the manufacture of stay tapes,especially useful in reenforcing the corners voi bre or cardboard boxes.The

forced to provide a substantially greater tensile v strength laterallyof the tape than longitudinally, without, at the same time, materiallyaffecting the flexibility of the tape in either direction, so that thetape may be fitted readily to the box comer.

A stay tape oi this character is frequently reenforced by a woven fabriccombined with a layer of paper forming the tape, the fabric and paperbeing usually combined in relatively wide strips which are then cutlongitudinally to form individual tapes of the desired width. In usingthe low grade of fabric customarily considered to be satisfactory, thewarp threads ci the fabric, which extend longitudinally of the pamr webas it is formed are not straight enough or suiciently widely spaced tolpermit cutting of the web between adjacent warp threads without cuttinginto certain of these threads. A further feature oi? the inventionresides in cutting the relatively wide web into narrow stay tapes ofsuitable Widths without cutting across any of the longitudinal threadsof the fabric, thus avoiding any iraying at the edge of the tape.

In a reenforced tape, the thickness of the comnpleted tape affects itsflexibility and also adects the amount of tape which can be wound into aroll of a predetermined diameter for use in boxmaking machinery. Toavoid these objections, one of the features of the present inventioninvolves the step of forcing the covering sheet, which extends over thereenforcing fabric, into close contact with the paper sheet on the otherside of the reenforcing fabric, the latter paper sheet having a smoothouter surface for attachment of the tape to the box. To accomplish thisthe covering sheet which is stretchable has the portions which engagewith the reenforcing material oiset from the normal plane of the sheetby passing the combined webs between rollers or other devices forpressing the covering sheet against the other paper sheet. 'y

Other and further objects and advantages of the invention will appearfrom the following detailed description taken in connection with theaccompanying drawing in which- Fig. 1 is a perspective view of a box towhich the completed stay tape of the invention is applied.

Fig. 2 is a sectional view through a completed stay tape embodying theinvention, `the thickness of the material being greatly exaggerated.

Fig. 3 is a plan view of a portion of a. completed web from which thestay tape is cut.

Fig. d is a perspective view of the type of fabric used in the formationof the stay tape.

Fig. 5 is a sectional view through the corner of the box of Fig. 1,showing the tape applied thereto, the thickness of the tape beinggreatly exaggel-ated.

Lilie reference characters refer to like parts in the dierent gures.

With reference first to Fig. l, the stay' tape i made in accordance withthe invention is applied to the corner of a box 2 where the front andside walls il and l of the box come together. The tape forms-areenforcement which prevents the box from tearing at the corner andholds the adjacent sides of the box together. As will be apparent, thetape must reeniorce the box especially in the direction of thereenforcing lines 5, which represent the reenforcing bres extendinglaterally of the stay tape, as this is the direction in which the box ismost liable to tear. The stay tape has adhesive applied 'to 'theunderside thereof for easy attachment to the box and is relativelynarrow since it is necessary only to have the tape extend far enoughover the adjacent side walls of the box to assure a secure adhesiveconnection between the box and the tape.

Referring now to Figs. 2 and 3, the stay tape is made up of a strip ofpaper of sufficiently heavy stock to present a smooth surface forcontact with the box, and to the underside of the paper 6 is applied asuitable dry adhesive i of any usual character, by which the stay tapemay be applied to the box.

On the upper side of the strip of paper 6 is positioned a Woven fabric 8by which the tape is reenforced in a lateral direction, the weit threads9, as will be apparent from Fig. 3, being more closely spaced than thewarp threads I0. On the upper side of the fabric 8 is a covering stripof paper I I, which is preferably flexible and stretchable in alldirections, as for example, the familiar crepe `paper which is formed toprovide stretch in every direction, one form of this paper being shownin the Lorenz Patent No. 1,548,783, dated August 4, 1925, and anotherform being shown in the Kemp Patent No. 2,008,182, datedJuly 16, 1935.Either of these patents describes a process for producing a paper whichis stretchable both longitudinally and laterally of the web. The stripsof paper 6 and Il are securely held together and to the fabric 8 by aflexible adhesive i 2 of a type which is preferably soluble in water,as, for example, adhesive containing latex or sago, such as thecommercially available Lotol" which is a colloidal suspension of latexin water and other solvents. As best shown in Fig. 2, the paper H ispressed against the paper 6 so that the paper I I is embossed where themain threads of the fabric are located. Between adjacent threads of thefabric the paper S is pressed close enough to the paper Il to adhere tothe loose fibres extending from the weft threads, these fibers beingprovided by a loose twisting of the weft threads. 'Ihe two sheets ofpaper are thus securely held together over substantially the entiresurface, thereby avoiding any looseness in either paper sheet. Thisattachment is possible, by reason of the stretchability of the paper il,without putting enough strain on the paper il to tear it and withoutdistorting the paper 8. The adhesive is used in as small quantities aspossible and still have the tape stay together.

In the formation of the stay tape, the paper strips [6 and il arepositively secured to each lother with the fabric 8 therebetween bypassing the composite web, from which the tape is subsequently cut,between opposed rollers, one of which has a hard surface and engagesthe'outer side of the sheet the outer side of the sheet li isrelativelysoft, preferably of rubber, so that the flexible paper i l maybe pressed inwardly toward the paper 5, thus forming indentations'in thepaper il between the adjacent threads of the fabric 6. Since the paperll is stretchable in all directions, it will be clear that portions ofthe paper can be oiset from the normal plane of the paper to asubstantial degree Without affecting the stretchability thereof andwithout increasing the stiiness of the tape. The adhesive i2, as shown,is preferably applied to the fabric so that only a small quantityofadhesive is necessary to hold the sheets and fabric together. It willbe understood that-the fabric need not be entirely impregnated with theadhesive so long as the outside of each of the threads of the fabric ismoistened with the adhesive to a sufficient extent to assure the properadhesion of the several webs of the tape together. l

As the tape is to be used on the cornersof a cox it must have itsgreatest strength in a lateral direction and the reenforcing fabric 8 isaccordingly formed with the warp threads, which extend longitudinally ofthe tape, placed a substantial distance apart and the weft threadsarranged relatively close together. One example of fabric of thischaracter is shown in Fig. 4 which shows a Leno-weave fabric having theweft threads I3 very close together and the warp threads I4 arranged inpairs which are spaced a substantial distance apart, this distance inthe preferred embodiment being 'V2 inch. Each pair of warp threads inthe Leno-weave consists of two independent threads I4 which, betweenadjacent iiller threads, cross each other not only in The other roll,which engages a plane perpendicular tov thefabric, but also in the planeof the fabric, so that, as shown in this figure, the weft threads aretightly held by the warp in a uniformly spaced arrangement, and there ispractically no lateral shifting of the warp threads on the weft threads.'In order to produce an extremely inexpensive stay tape it is preferableto formthe warp threads of relatively light cotton thread and to makethe weft threads of jute, which is much less expensive than cotton. Theweft threads can accordingly be arranged relatively close together toprovide a stay tape which has a great amount of strength laterallywithout making the tape objectionably expensive. The strength of thetape is obviously controlled by the spacing of the weft threads. Theweft threads preferably have a large number of loose ibre ends, acharacteristic of jute threads, so that the weft threads are securelyheld against movement relative tothe paper by the adhesive engaging withthese bres. The number and length of the'loose fibres is obviouslycontrolled by the amount of twist given to the thread.

In the formation of stay4 tapes thefabric is preferably made up in weiof much greater width than the stay tape, and the sheets of paper l andil of si'milar width are applied to opposite sides of the full widthweb. After the sheets of paper e and il have been applied to theopposite sides of the fabric 8 the composite material is still muchWider than the desired width for the .stay tapes and the material isaccordingly cut withoutany possibility of any of the warp threads beingcut during the formation of the tape. Obviously the Warp threads form alongitudinal reenforcement for the tape' so that the tape may in certaininstances be used in sealing box covers as well as in reenforcing thecorners.

Although it has been pointed out above that the adhesive used inattaching the paper sheets to the fabric is preferably a water solubleadhesive, it will be apparent that other types of adhesive, such asthermo-plastic adhesives may equally well be used and. in fact, in theproduction of an extremely inexpensive type of stay tape, where the useof asphalt is not objectionable, it is possible to use asphalt or othersimilar thermoplastic adhesives.

In the production `of` these stay tapes at a low 'cost it is desirableto crepe the paper Il just prior to the attachment of theseveralthicknesses of material together, and in the same machine. It isaccordingly essential that the adhesive used be of a type which willpermit the creping of the paper H and the immediate application of thefabric 8 and paper 6 thereto without the necessity for drying the crepedpaper l I and vsubsequently applying a special adhesive thereto. A`Inthe use of a thermoplastic adhesive the latter may also form the bondwhich secured the paper' to the creping drum during the creping processand it will be apparent that Water soluble adhesives'may also be usedfor the same purpose with 'the paper immediately thereafter applied tothe remainder of the materials making the stay tape Without thenecessity for drying the crepe paper l l. It will be apparent that theadhesive on the creped paper will aid in securing the crepe janais-,loss paper to thesmth paper sheet betwlfth 4 .y Y

H .area-jef he taytapejlK Furtv her, the exibility of l fithe ad esivvand vofthe' paper H Permits the to cover and protect the woven iabriandthusvv threads ofthe fabric. 0,' The creped or stretchable paper Il isarranged prevent any threads of the fabricffrom being caught and pulledaway from the box.' .The paper Il also protects the adhesive so thatfthelatter does not appear on .the surface ofthe iin` ished tape and canthen, if necessary, bean undesirable color without affecting thelsaliabilityV of the tape. In order that the tape: may be]` readilysalable it can be produced in ariydesired-l color merely by making thepaper llthe desired color before forming the tape. Since the paper Ilfully covers the tape, contrasting colors ong paper provided on itsoutside with adhesive for attachment to the box corner has'a smoothoutside surface for positive engagement with the box material over theentire surface of `thetape. Moreover, since the paper sheet il isstretchable the stay tape can be bent around" the "corner of the boxwithout the formation of objectionable creases in the paper sheet 6, sothat the paper sheets A' rlhei'ethe box over theentire nforeing'bresofthe woven .fabric ,Y v ly relative'to the paper 6 so 'that he Apaper `isallowedlto': bend aroundv the' corner of theboxwltho'ut"thelformation ofanyI objecjtionable `creases -in ythe paper 6. vThe*.'repedVwhen:uricreped' and fthe-showing of Fig. 5 indi catesy Lanfi'- absence"of Qc' 4"stay tape `by a relativelpthinner paper at this f point.Itfwlll be understood that the adhesive ses at the bend in the on thevoutside of the paper sheet E may be omitted and applied to the staytape at the time that the tape is applied to the box.

I claim,

In the formation of a. stay tape, the steps which involve securingtogether a main paper sheet, a woven fabric and a stretchable papersheet in superposed relation, with a stretchable adhesivebetweerrthesheets, and passing said .combined fabric between a pair ofrolls, one d"`su'1face and engaging the main andthe other having aresilient p vsurface'v'arjlengaging the stretchable paper sheet'topress-fthe stretchable paper sheet around the thre'ads'of the fabricand against the main sheet.

HENRY ATWATER.

